Here's an example of a product that would do what's being talked about:
http://svconline.com/mag/avinstall_chyron_chytv/
Also, using any of Blackmagic Design's I/O boards, via hardware and software, you can superimpose anything.
We lead our customers away from doing that, but the fact is that the manufacturers of these products haven't really grasped the possible implications of what they are selling.
That said, there are products on the market that allow you to display a feed of video, and add your information and branding around it. It's very useful, when used in a legal way. For example, if your a city government, and you want to pipe your city cable channel into your courthouse, but also combine a list of upcoming court cases for a courtroom - volia - supply the feed, the data feed, run it through a box like Chyron ChyTV, and send it to your signage display.
Videographer/Editor
Creative Director
Union Digital, Inc.
http://www.uniondigitalmedia.com
